1. Associate Professor, Del E. Webb School of Construction, Ira A. Fulton School of Engineering, Arizona State Univ., Tempe, P.O. Box 870204, AZ 85287-0204 (corresponding author).
2. Territory Manager (Asia), Earth Tool Company LLC, P.O. Box 3, Oconomowoc, WI 53066.
3. Executive Director, Balama Prima Engineering Company Ltd., 68-74 Bonham Strand East, Sheung Wan, Hong Kong.